George b



G. B. ST. JOHN.

HEAT REGULATOR FOR INGUBATORS. I

(No Model.)

Patehted Nov. 23.

UNITED STATES PATENT V OFFI E.

GEORGE E. ST. JOHN, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE STANDARD THERMOMETER COMPANY.

HEAT-REGULATOR FOR INCUBATORS.

ESPECIE'IC'ATION forming part of Letters Patent No. 353,272, dated November 23, 1886. Application tiled August 2|, 1885. Serial No. 175,179. (No model.)

To all whom it may concern:

Be it known that I, Gnonen B. ST. J OI-IN, of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Heat-Regulators for Incubators, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts. 7

My invention has for its object to prevent the overheating of incubators.

In my improved apparatus the temperature of the incubator is lowered whenever itreaches a predetermined point, the temperature being lowered before the degree of heat becomes harmful.

Incubators have heretofore been supplied with automatic temperature-regulating mech anism for effecting precisely this result, and

hence I make no broad claim to such invention, my invention, consisting in the peculiar construction and arrangement of apparatus to this end, substantially as I will now proceed to particularly set forth and claim.

In accordance with my invention an incubator of any usual or known form is provided with an outletpipc for the heated air, the said pipe (shown as provided with a collar or flange and held in adjusted position within the incubator) being provided with a damper, which acts to prevent the escape of the air so long as it is heated only to the normal or required temperature. The damper referred to is shown as elliptical in shape, and is secured to a shaft turning in bearings in the said pipe, the said shaft being provided with an adjustable counter-weight, which normally acts to turn the said damper so as to close the outletpipe. To allow the air to escape when it has become abnormally heated, I have placed within the incubator a thermostatic instrument, substantially such as descri bed in United States Patent No. 330,161, dated NovemberlO,

1885, granted to Thomas W. Shepherd, its sensitive coil and arbor, rotated by the said coil, movingapointer to strike a lug or finger on the damper shaft, thereby turning the damper and opening the outlet-pipe when the said sensitive helical coil is acted upon by the increased temperature of the incubator. The thermostat is not herein broadly claimed.

Figure l is a sectional elevation of an incubator provided with my improved apparatus, the lower half of the damper being shown in dotted lines. Fig. 2'is a section of Fig. 1 on the line 00 x, and Fig. 3 is a rear view of the thermostatic instrument.

The frame A, steam-pipe 1?, support E, and water-vat V are and may be of any usual construction common to incubators. The pipe B, extended into the incubator and having a flange, b, resting upon the top of the frame A, is provided with a shaft, (1, having its hearings in the said pipe, the said shaft having connected to it a damper, 1), (shown as elliptical in form,) the said damper being normally held in position to close the passage of the pipe B by means of a counter-weight, W, (see Figs. 1 and 2,) fastened to the shaft (1, and adjustable thereon by means of a screw, 8.

I have placed within the incubator a thermostatic instrument, T,.substantial]y such as described in United States patent referred to, its sensitive coil f and arbor e rotated by the said coil according to variations in temperature, moving a pointer, b, to strike a lug or finger, a, on the damper-shaft d, thereby turning the shaft (1 and damper D, opening the, passage H of the pipe B, and allowing the escape of air when the latter is heated above the point at which it is desired the temperature of the incubator should be maintained.

The thermostat T is maintained in position within the incubator by means of arms (0 a, secured to the frame h of the thermostat, and provided withforksfQwhic h encircle the pipe 13, and are clamped together by means of the screws 11. n.

\Vhen the temperature of the incubator, heated by air which enters the chamber K through the openings a a, and which, after circulating around the steam-pipe P, enters the incubator proper by passages (6", only one of which is shown, has risen to a predetermined point, which point I shall call the danger point, the pointer Z of the thermostat T is oscillated by the aetion of the heat upon the sensitive helical coil f, which heat expands the said coil and rotates the arbor c", causing the pointer to strike against the finger a, as shown in Fig. 1, which. rotates the shaft tion to afford an outlet for the heated air in the incubator, the escape of the heated air effecting the lowering of the temperature with-.

in the incubator to below the danger point. 5 When the temperature of the incubator has again become normal,the sensitive helical coil, contracting, removes the pointer b from the finger a, allowing the weight W to act upon the shaft d and damper D, to prevent the up 10 ward passage of air in the pipe 3. This action is repeated as often as the temperature of the incubator reaches or nearly reaches the danger point, 7 i The opening and closing of the passage in the 15 pipeB can be regulated to maintain any desired temperature by adjusting the finger a on the shaft 12, and by means of the micrometer-screw g and attachment g.

I claim 2o 1. The combination, with the frame A and pipe B,set therein, of a damper, D, a dampershaft, (1, in said pipe, a counter-balance, W, and pin a on said shaft, and a thermostat provided with an arm, I), to engage the said pin to open the damper at an undue rise in temperature, 25 substantially as described.

2. The frame A, pipe B, and a damper arranged in said pipe, a damper-shaft, and a pin, a, thereon, combined with the thermostat T, having a pointer, Z1, and the arms a aflsecured to said thermostat and engaging the pipe, substantially as and for the purpose described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

GEO. B. ST. JOHN.

Witnesses:

GEO. HoLMAN, EDGAR W. UPTON. 

